Rectifier roll



Sept. 4, 1951 1 HoRNBosl-El. 2,566,449

RECTIF'IER ROLL Filed June 25, 1946 IN VEN TOR. l 1. oro HaefveosrELPatented Sept. 4, 1 951 Lloyd Hornbostel, Beloit, Wis., assigner toBeloit Iron Works, Beloit, Wis., a corporation of WisconsinApplicationjune 26, 1946, Serial No. 679,419

4Si Claims. l

This invention relates to paper making ma-l chine rectifier rollconstructions for increasing the permissible speed of operation of papermachinery by correcting or rertifying the condition of stock immediatelybefore it is deposited on the forming surface of the paper machine sothat very little if any additional conditioning or rectifying of thestock need be done on the forming surface. Specifically the inventiondeals with a rectifier roll construction which insures the uniformfeeding of paper stock across the entire width of a paper formingsurface and eliminates heretofore encountered drag effects on stock flowadjacent the edges of the forming surface.

According to this invention a rectifier roll is rotatably mounted in thestock inlet of a paper machine immediately in advance of the finaldischarge outlet and as close. to the forming wire of the machine as ispossible. The rectifier roll is composed of a perforated tube and aplurality of spaced parallel disks extending transversely across theinterior of the tube with the outermost disks being spaced inwardly fromthe ends of the tube. The ends of the tube have relatively closeoperating clearance relationship with the side walls of the inlet. Thetube is perforated along its entire length and around its entireperiphery. The perforations decrease in size inwardly from the ends ofthe tube. The very ends of the tube are scalloped with semi-holes. Stockfrom the inlet must flow through the tube before it can reach theforming surface of the machine. Heretofore, friction drag effect of theside walls of the inlet on the stock caused stock flow conditions whichwere more rapid intermediate the side edges than at the side edges. As aresult uneven stock formation took place initially on the wire and hadto be corrected by shaking the wire, by providing prolonged formingtime, and the like, thereby slowing up production of the machine. 'I'hepresent rectifier rolls eliminate the heretofore encountered drag effectby eliminating end heads on the roll and by so graduating the holes inthe roll that the stock stream meets the identical resistance across itsentire width and is evenly fed to the forming surface at a singleselected velocity` As a result the stock is in good condition forimmediate forming into paper and can be set immediately into a sheet onthe forming surface. 'I'his of course permits faster operation of themachine because mechanical correcting conditions and the time necessaryto permit the correcting operations are eliminated. The rectifier rollsof this invention put the stock on the forming surface in a form readyfor immediate setting into a paper sheet.

It is then an object of this invention to provide a headless rectifierroll.

A further object of this invention is to provide a rectifier roll4construction for paper making machines which has perfor-ations ofdecreasing size extending inwardly from the ends thereof.

Another object of the invention is to provide a rectifier roll for thefeed boxes of lpaper making machines which is composed of a perforatedtube and a plurality of spaced disks extending transversely in the tubeand inwardly from the ends of the tube to direct fIow of stock throughthe tube.

Another object of the invention is to provide .a rectifier roll for thestock inlet of a Fourdrinier type paper making machine which has aperforated tube receiving stock as it ows out of the inlet and whichcontains a plurality of spaced parallel bailles to direct the stocktransversely through the tube thereby eliminating cross flow effects.

Another object of the invention is to provide a rectifier rollconstruction which eliminates the skin drag effect heretoforeencountered in connection with the feeding of paper stock onto theforming wire of a paper making machine.

Other` and further objects of the invention will be apparent to thoseskilled in the art from the following detailed description of theannexed sheet of drawings which, by way of a preferred example,illustrates one embodiment of the invention.

In the drawings:

Figure 1 is a somewhat diagrammatic vertical cross sectional view of thewet end of a paper making machine having a stock inlet equipped with arectifier roll according to this invention.

Figure 2 is an axial cross sectional view, with parts in elevation, ofthe rectier roll of this invention and illustrating the manner in whichthe roll is mounted relative to the side wall of the stock inlet.

Figure 3 is a plan view of the rectifier roll of this invention andillustrating the same mounted on the side walls of the stock inlet.

As shown on the drawings:

In Fig. 1 the reference numeral I0 designates a head box or stock inletfor a Fourdriniei` type paper making machine including a forming wire II and a breast roll I2. The inlet I0 has a bottom wall I3 extendingrearwardly from the upper run of the forming wire I I behind the breastroll I2. Side walls I4 extend upwardly from the bottom wall I3. A backwall i5 extends'between the side walls I 4 at the rear end of the bottomwall I3. A front wall IB is provided on the front end of the box. Thetop is closed by a top Wall I1 which has an aperture or doorway Ilaclosed by a door I8. A pipe I9 extends from the top wall l1. charge endof a feed pipe 20. A slice 2| is carried by the front wall I6 inspaced'relatio'n above the upper run of theforming wire II at'the breastroll I2. An apron 22 is carried by the The bottom wall I3 receives thedis- 3 bottom wall I3 and extends forwardly over the breast roll I2.

The inlet I therefore has a closed chamber 23 for stock-'receivedthrough the inlet pipe 20. The stock ilows onto the wire Il at thebreastlroll I2 through a. discharge opening or outlet nozzle 24 providedbetween the front edge of the apron 22 and the bottom edge of the slice2|. Stock in the chamber 23 may be subjected to pressure by admittingcompressed air or other gas into the chamber on top of the stock throughthe pipe I9.

In accordance with this invention a rectier roll 25 is rotatably mountedin the chamber 23 immediately adjacent the outlet 24 so as to rectify orcondition stock owing from the chamber 23 to the outlet 24.

As best shown in Fig. 2 the rectifier roll 25 is composed of a metaltube 26 preferably formed of corrosion resistant metal such as brass,bronze, corrosion resistant steel, or the like. The tube 28 iscylindrical and receives a plurality of circular metal disks 21 atspaced intervals along the length thereof. These disks 21 extendtransversely of the tube interior and are welded to the tube at variouspoints such as 28. The end disks such as the disk 21a may be somewhatthicker than the intermediate disks but are spaced inwardly from the endedges 26a of the tube. These end disks are centrally apertured at 23.Blocks such as 30 are interposed between each end disk 21a and the nextadjacent disk 21 and are welded thereto as at 3|. Each block 30 has atapered recess 32 extending inwardly from the end face of the block thatis secured to the disk 21a. The recess 32 is aligned with the aperture23 and converges to a back wall or bottom shoulder 32a. A threaded well33 extends axially inward from the back wall 32a.

The end edges 26a of the tube 26 are disposed closely adjacent the sidewalls I4 of the inlet I0 and an axle 34 projects from the ends of thetube through each side wall I4 and through a bearing sleeve 35 carriedin a housing 36 secured on the outer face of each side wall. The outerend of the housing 36 is closed by means of a screw cap 31. The axle 34has a tapered head portion 34a on the inner end thereof fitting throughthe aperture 28 and snugly seating in the recess 32.

A bolt 38 projects through the axle 34 and has a threaded end 38athreaded into the well 33. A head 38h is provided adjacent the threadedend 38a and is bottomed on the wall or shoulder 32a. The outer end head38c is adapted to be engaged by a wrench for threading the end 38a.tightly in the well 33. The head 38e is adapted to fit through the axle34 and projects beyond the end of the axle. A nut 39 is threaded on theouter end of the bolt 38 into thrusting engagement with the end face ofthe axle 34 to force the head 34a thereof into tight wedging engagementwith the recess 32. A lock nut 4U coacts with the nut 39 to hold thesame in tight position.

'Ihe axle projecting through the rear wall I4 is longer than the axleprojecting through the front wall I4, as shown in Fig. 3, and receives agear 4I thereon for driving the roll.

As shown in Fig. 3 the ends 26a of the tube must have operatingclearance relationship with the side walls I4 since the tube rotatesrelative to the side walls. Heretofore rectier rolls were equipped withend heads and the spaces between these end heads and side walls of astock inlet in which the roll was mounted aiorded restricted passagewaysfor the flow of stock. These restricted passageways, being bounded onone side by a stationary wall and on the other side by a rotatingsurface, disturbed even flow of stock and created a stock conditiondiffering from the condition of a. main body of stock flowing throughthe roll. 'As a result the outer edges of the flowing stream of stockcontained stock in a different condition than the main body of stockbetween said edges. Further, the stationary side walls, such as thewalls I4 of the stock inlet, have a. frictional drag effect upon thestock tending to impede its forward ow through the outlet 24 onto theforming wire II and the main body of stock between the side edgestherefore normally has a faster flow rate than the side edges.

In the present invention, however, the end heads of the rectifier rollhave been eliminated and the first supporting disks have been spacedinwardly from the ends of the tube as shown in Fig. 2 so that the edges26a of the tube are free and uncovered. The passageways 42 between theedges 26a and the walls I4 are thereby bounded on one side by thestationary wall I4 and on the other side only by the relatively thinedges of the tube. As a result the disturbing influences on the stockare reduced to a minimum.

In accordance with this invention the tube 23 is perforated with holesthat decrease in diameter inwardly from the edges 2Ba`of the'tube. Holes43 are formed in the very edges 26a of the tube to provide a scallopededge. These holes 43 have full communication with the lpassageways 42 toopen up flow of stock through the Apassageway at the identical rateoccurring along the entire length of the roll. 'I he h'oles 43 extendradially and as shown are semi-circular holes, Additional full circularholes 44 extend radially through the tube 26 and decrease in diameterfrom the ends of the tube to the middle of the tube. The holes 44 are sograduated as to create a uniform rate of ow through the outlet 24 of theinlet I 0 across the entire width of the inlet be tween the side wallsI4. Thus free flow through the middle section of the tube 26 is impededby the smaller holes 44 to compensate for frictional drag imposed by thestationary side walls at the outer ends of the tube. These outer ends ofthe tube have larger holes therethrough and have `open passageways 42 atthe ends thereof all of which coact to maintain a uniform flow riteacross the entire machine.

The disks 21 and 21a provide bailles which i sure radial iiow of stockthrough the tube and prevent development of crossrlow or eddy currentconditions.

The rectier roll 25 can be driven in either direction as desired. It ispreferably rotated at a rate faster than the rate of ow of stocktherethrough.

The rectifier rolls of this invention have eliminated all skin orfrictional drag eiects on stocks caused by the walls of a stock inlet.They have corrected uneven stock flow conditions and have conditionedthe stock so that it can'be immediately set into a paper sheet. As aresult machines equipped with rectifier rolls of this invention can berun much faster to produce a better quality of paper than was possibleeven at the slower speeds.

` It will, of course, be understood that various details of constructionmay be varied through a wide range without departing from the principlesof this invention, and it is, therefore, not the purpose to limit thepatent granted hereon otherwise than necessitated by the scope of theappended claims,

I claim as my invention:

1. A rectifier roll construction for a paper making machine comprising aperforated metal tube, a. pair of radially extending disks in spacedopposed relation in said tube inwardly from the end of the tube, theoutermost of said disks having a central aperture therethrough, arecessed block extending between said disks and secured thereto, saidrecessed block having a threaded inner end and a tapered outer end, anaxle having a tapered head projecting through the aperture in theoutermost disk and snugly seated Vin the tapered portion of the recessof said block, a bolt extending through said axle and threaded into thethreaded inner end of the recess of said block, and a nut threaded onsaid bolt acting on the outer end of the axle to force the same intowedged engagement in the tapered recess.

2. A rectifier roll for a paper making machine comprising a perforatedtube having perforated edges providing scalloped ends, spaced paralleldisks in said tu'be 4providing radial baffles therein, and the outermostdisks being spaced inwardly from the ends of the tube to provideunobstructed outer ends for said tube.

3. In a paper machine stock inlet having an interior space for the flowof stock therethrough defined by opposed side walls, and bottom, frontand rear Walls, the improvement of a rectifier roll extendingtransversely thereacross and having open end faces in closely spacedrela .ion to said side walls, a pair of baffles each extending radiallyacross the interior of said roll axially inwardly from the correspondingopen end face thereof, and a stub axle extending through each of saidside walls into the adjacent end of said roll, said axles being securedto said baffles to rotatably support said roll while leaving open theends of said roll to eliminate friction drag effects on stock flowingthrough the inlet immediately adjacent said side walls.

4. In combination with a paper machine stock inlet adapted for the flowof stock therethrough and having opposed side walls, a bottom wall anda. front wall cooperating with said bottom wall to define a stock outletopening immediately adjacent a forming wire, the improvement of arectifier roll mounted in said inlet immediately adjacent the outletopening thereof .to rectify stock flowing therefrom onto said wire, saidrectifler roll comprising an elongated cylindrical tube extendingtransversely across said inlet and having scalloped open ends closelyspaced from said side walls to eliminate frictional drag ex- 6. Incombination with a stock inlet having a discharge outlet, a rectifierroll mounted in said inlet to extend transversely thereacrossimmediately adjacent said outlet, said rectifier roll havingunobstructed scalloped open ends in close- 1y spaced clearance relationto the sides of the inlet together with graduated surface perforationsof diminishing size inwardly from said ends to the center thereof, saidperforations being arranged to maintain a uniform stock flow rate acrossthe entire width of the outlet, and said unobstructed scalloped openends eliminating stock drag effects along said sides.

7. A roll for rectfying stock flow throughs. stock space having spacedside, bottom and end walls comprising an open-ended perforated tubehaving perforations around the circumference of the tube open end facesto form a scalloped open end in close running spaced relation to saidside walls, the scalloped open ends of said tube cooperating with saidwalls to provide for the flow of stock radially of said tube immediatelyadjacent said side walls.

8. A roll for rectifying stock flow through a paper machine comprisingan elongated perforated cylindrical tube having unobstructed ends andperforations therethrough diminishing in size axially inwardly from saidopen ends, and axially spaced parallel ballie disks transverselyspanning the interior of the tube and engaging the tube around theircircumferences to divide the roll interior into a plurality of chambersincluding an open-ended chamber at each terminal end of the tube,saidperforations accommodating the passage of stock through said chambers,said baffles channelling stock flow therethrough, and said open-endedchambers accommodating 4stock ow radially of said tube at the extremeends thereof, the stock being emitted from each of said roll chambersthrough holes of substantially the same size as those through which itentered.

9. In a paper machine stock flow inlet having side and end closure wallsdefining a stock space. a rectifier roll mounted in said stock space andadapted to rectify stock contained therein.' the rectifier rollcomprising an elongated perforated cylindrical tube having unobstructedends and perforations progressively diminishing vin size axiallyinwardly from said ends, and axially f spaced baille disks extendingradially across the erted on stock flowing through the inlet adjacentsaid side walls by said roll, said tube also having perforationstherethrough along the length there:m of for stock flow radially throughthe tube. said perforations diminishing in size axially inwardly fromeach of said open ends to the center thereof. 6o

of the tube, and the outermost disks being spaced 10 inwardly from theends of the/tube to accommodate uniform radial stock flow through thetube across the width of the tube including lthe extreme end portionsthereof.

interior of said tube, the end baille disks 'being spaced inwardly fromthe ends of said tube, said perforated tube creating a uniform stockflow rate across the entire width of said roll and said` open endsextending into close running spaced relation to the side walls of saidstock space. thus accommodating stock now radially oi' said tube alongsaid side walls.

LLOYD HORNBOS'I'EL.

REFERENCES CITED The following references are of record in the le ofthis patent:

UNITED STATES `PATENTS Number Name Date 235,546 Marsh Dec. 14, 1880 V424,342 McNamar Mar. 25, 1890 763,251 Breck June 21, 1904 1,519,559Stewart Dec. 16, 1924 1,526,193 Voith Feb. 10, 1925 1,771,600 Yoder July29, 1930 2,390,977 Williams Dec..11, 1945 2.t40f127k Rosmait May 4, 1948

